var backBtn = null;
//返回上一个地址
$(function () {
    backBtn = $("#back");
    backBtn.on("click", function () {
        //alert("view : "+referer);
        if (referer != undefined
            && null != referer
            && "" != referer
            && "null" != referer
            && referer.length > 4) {
            window.location.href = referer;
        } else {
            history.back(-1);
        }
    });
});